The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Engine control systems monitor crankshaft position. Rotational speed of the crankshaft (engine speed) and crankshaft acceleration can be determined based on the crankshaft position. For example only, fueling, ignition timing, throttle opening, and/or other engine parameters may be controlled based on the crankshaft position, the engine speed, and/or the acceleration.
A crankshaft position monitoring system typically includes a control module (e.g., an engine control module), a crankshaft sensor, and a toothed wheel that rotates with a crankshaft. The toothed wheel may have N number of teeth, and the crankshaft sensor may monitor passing of the teeth. The crankshaft sensor generates pulses in a crankshaft position signal as the teeth of the toothed wheel pass the crankshaft sensor.
The control module determines the crankshaft position based on the pulses in the crankshaft position signal. The control module may determine the crankshaft position at various crankshaft rotation intervals. As an example, the control module may determine the crankshaft position at intervals of greater than or equal to 90° of crankshaft rotation. The resolution of the crankshaft position signal (e.g., number of samples per crankshaft revolution) increases as the intervals decrease.